<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script>
    'use strict'

    var a=12;
    if(a%2==0){
      function show(){
        alert('a是偶数');
      }
    }else{
      function show(){
        alert('a是奇数');
      }
    }

    show();
    </script>
  </head>
  <body>

  </body>
</html>
